workqueue: implement worker_{set|clr}_flags()

Implement worker_{set|clr}_flags() to manipulate worker flags.  These
are currently simple wrappers but logics to track the current worker
state and the current level of concurrency will be added.

Signed-off-by: Tejun Heo <tj@kernel.org>

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index e697d6c72daacfd1f0e7ecca67f5d5640a52966d..4c31fde092c6389a58780a2659154cbe60dd9363 100644 (file)
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -411,6 +411,38 @@ static void wake_up_worker(struct global_cwq *gcwq)
                wake_up_process(worker->task);
 }
 
+/**
+ * worker_set_flags - set worker flags
+ * @worker: worker to set flags for
+ * @flags: flags to set
+ * @wakeup: wakeup an idle worker if necessary
+ *
+ * Set @flags in @worker->flags.
+ *
+ * LOCKING:
+ * spin_lock_irq(gcwq->lock).
+ */
+static inline void worker_set_flags(struct worker *worker, unsigned int flags,
+                                   bool wakeup)
+{
+       worker->flags |= flags;
+}
+
+/**
+ * worker_clr_flags - clear worker flags
+ * @worker: worker to set flags for
+ * @flags: flags to clear
+ *
+ * Clear @flags in @worker->flags.
+ *
+ * LOCKING:
+ * spin_lock_irq(gcwq->lock).
+ */
+static inline void worker_clr_flags(struct worker *worker, unsigned int flags)
+{
+       worker->flags &= ~flags;
+}
+
 /**
  * busy_worker_head - return the busy hash head for a work
  * @gcwq: gcwq of interest
@@ -776,7 +808,7 @@ static void worker_enter_idle(struct worker *worker)
        BUG_ON(!list_empty(&worker->entry) &&
               (worker->hentry.next || worker->hentry.pprev));
 
-       worker->flags |= WORKER_IDLE;
+       worker_set_flags(worker, WORKER_IDLE, false);
        gcwq->nr_idle++;
 
        /* idle_list is LIFO */
@@ -800,7 +832,7 @@ static void worker_leave_idle(struct worker *worker)
        struct global_cwq *gcwq = worker->gcwq;
 
        BUG_ON(!(worker->flags & WORKER_IDLE));
-       worker->flags &= ~WORKER_IDLE;
+       worker_clr_flags(worker, WORKER_IDLE);
        gcwq->nr_idle--;
        list_del_init(&worker->entry);
 }
@@ -890,7 +922,7 @@ fail:
  */
 static void start_worker(struct worker *worker)
 {
-       worker->flags |= WORKER_STARTED;
+       worker_set_flags(worker, WORKER_STARTED, false);
        worker->gcwq->nr_workers++;
        worker_enter_idle(worker);
        wake_up_process(worker->task);
@@ -920,7 +952,7 @@ static void destroy_worker(struct worker *worker)
                gcwq->nr_idle--;
 
        list_del_init(&worker->entry);
-       worker->flags |= WORKER_DIE;
+       worker_set_flags(worker, WORKER_DIE, false);
 
        spin_unlock_irq(&gcwq->lock);
 
@@ -2214,10 +2246,10 @@ static int __cpuinit trustee_thread(void *__gcwq)
        BUG_ON(gcwq->cpu != smp_processor_id());
 
        list_for_each_entry(worker, &gcwq->idle_list, entry)
-               worker->flags |= WORKER_ROGUE;
+               worker_set_flags(worker, WORKER_ROGUE, false);
 
        for_each_busy_worker(worker, i, pos, gcwq)
-               worker->flags |= WORKER_ROGUE;
+               worker_set_flags(worker, WORKER_ROGUE, false);
 
        /*
         * We're now in charge.  Notify and proceed to drain.  We need
@@ -2324,10 +2356,10 @@ static int __devinit workqueue_cpu_callback(struct notifier_block *nfb,
 
                /* clear ROGUE from all workers */
                list_for_each_entry(worker, &gcwq->idle_list, entry)
-                       worker->flags &= ~WORKER_ROGUE;
+                       worker_clr_flags(worker, WORKER_ROGUE);
 
                for_each_busy_worker(worker, i, pos, gcwq)
-                       worker->flags &= ~WORKER_ROGUE;
+                       worker_clr_flags(worker, WORKER_ROGUE);
                break;
        }